fix(clients): honor project default models in new threads

apps/mobile/src/features/threads/NewTaskDraftScreen.tsx

@@ -704,10 +704,12 @@ export function NewTaskDraftScreen(props: {
       if (editingPendingTask) {
         flow.finishEditingPendingTask();
       } else {
-        // Drop the workspace selection with the content: the next task should
-        // re-resolve mode/branch/origin from the server's configured defaults
-        // instead of resurrecting this task's picks.
-        clearComposerDraftContent(draftKey, { clearWorkspaceSelection: true });
+        // Drop draft-local model/workspace selections with the content. The
+        // next task re-resolves project defaults before sticky app defaults.
+        clearComposerDraftContent(draftKey, {
+          clearModelSelection: true,
+          clearWorkspaceSelection: true,
+        });
       }
       navigation.getParent()?.goBack();
       return;
@@ -771,7 +773,10 @@ export function NewTaskDraftScreen(props: {
       }
       flow.finishEditingPendingTask();
     } else {
-      clearComposerDraftContent(draftKey, { clearWorkspaceSelection: true });
+      clearComposerDraftContent(draftKey, {
+        clearModelSelection: true,
+        clearWorkspaceSelection: true,
+      });
     }
     navigation.dispatch(
       StackActions.replace("Thread", {

apps/mobile/src/features/threads/new-task-flow-provider.tsx

@@ -33,6 +33,7 @@ import {
   buildModelOptions,
   groupByProvider,
   resolveDefaultableModelSelection,
+  resolveNewTaskModelSelection,
   resolveSelectableModelSelection,
 } from "../../lib/modelOptions";
 import { scopedProjectKey } from "../../lib/scopedEntities";
@@ -48,8 +49,10 @@ import {
   removeComposerDraftAttachment,
   replaceComposerDraftAttachments,
   setComposerDraftText,
+  setStickyComposerModelSelection,
   updateComposerDraftSettings,
   useComposerDraft,
+  useStickyComposerModelSelection,
 } from "../../state/use-composer-drafts";
 import { useDebouncedValue, usePaginatedBranches } from "../../state/queries";
 import { vcsEnvironment } from "../../state/vcs";
@@ -418,21 +421,33 @@ export function NewTaskFlowProvider(props: React.PropsWithChildren) {
     selectedEnvironmentServerConfig,
     selectedProject?.defaultModelSelection ?? null,
   );
+  const storedStickyModelSelection = useStickyComposerModelSelection();
+  const stickyModelSelection = resolveDefaultableModelSelection(
+    selectedEnvironmentServerConfig,
+    storedStickyModelSelection,
+  );
   const modelOptions = useMemo(
     () =>
       buildModelOptions(
         selectedEnvironmentServerConfig,
-        draftModelSelection ?? projectDefaultModelSelection,
+        draftModelSelection ?? projectDefaultModelSelection ?? stickyModelSelection,
       ),
-    [selectedEnvironmentServerConfig, draftModelSelection, projectDefaultModelSelection],
+    [
+      selectedEnvironmentServerConfig,
+      draftModelSelection,
+      projectDefaultModelSelection,
+      stickyModelSelection,
+    ],
   );
 
-  const selectedModel =
-    draftModelSelection ??
-    projectDefaultModelSelection ??
-    modelOptions.find((option) => option.isDefault)?.selection ??
-    modelOptions[0]?.selection ??
-    null;
+  // An unsent draft keeps its explicit pick. Fresh drafts resolve the project
+  // default before the last manual app-wide selection and provider default.
+  const selectedModel = resolveNewTaskModelSelection({
+    draftSelection: draftModelSelection,
+    projectDefaultSelection: projectDefaultModelSelection,
+    stickySelection: stickyModelSelection,
+    modelOptions,
+  });
   const selectedModelKey = selectedModel
     ? `${selectedModel.instanceId}:${selectedModel.model}`
     : null;
@@ -462,9 +477,9 @@ export function NewTaskFlowProvider(props: React.PropsWithChildren) {
       if (!option) {
         return;
       }
-      updateComposerDraftSettings(selectedProjectDraftKey, {
-        modelSelection: options ? { ...option.selection, options } : option.selection,
-      });
+      const selection = options ? { ...option.selection, options } : option.selection;
+      updateComposerDraftSettings(selectedProjectDraftKey, { modelSelection: selection });
+      setStickyComposerModelSelection(selection);
     },
     [modelOptions, selectedProjectDraftKey],
   );
@@ -482,6 +497,7 @@ export function NewTaskFlowProvider(props: React.PropsWithChildren) {
       updateComposerDraftSettings(selectedProjectDraftKey, {
         modelSelection: nextSelection,
       });
+      setStickyComposerModelSelection(nextSelection);
     },
     [selectedModel, selectedProjectDraftKey],
   );

apps/mobile/src/lib/modelOptions.test.ts

@@ -1,12 +1,14 @@
 import { describe, expect, it } from "vite-plus/test";
 
-import { ProviderInstanceId, type ServerConfig } from "@t3tools/contracts";
+import { ProviderInstanceId, type ModelSelection, type ServerConfig } from "@t3tools/contracts";
 
 import {
   buildModelOptions,
   groupByProvider,
   resolveDefaultableModelSelection,
+  resolveNewTaskModelSelection,
   resolveSelectableModelSelection,
+  type ModelOption,
 } from "./modelOptions";
 
 describe("mobile model options", () => {
@@ -171,4 +173,30 @@ describe("mobile model options", () => {
     // Offline: nothing to validate against, selection passes through.
     expect(resolveDefaultableModelSelection(null, legacy)).toBe(legacy);
   });
+
+  it("resolves new tasks from draft, project, sticky, then provider defaults", () => {
+    const draft = { instanceId: ProviderInstanceId.make("codex"), model: "draft" };
+    const project = { instanceId: ProviderInstanceId.make("codex"), model: "project" };
+    const sticky = { instanceId: ProviderInstanceId.make("codex"), model: "sticky" };
+    const providerDefault = {
+      selection: { instanceId: ProviderInstanceId.make("codex"), model: "default" },
+      isDefault: true,
+    } as ModelOption;
+    const resolve = (
+      draftSelection: ModelSelection | null,
+      projectDefaultSelection: ModelSelection | null,
+      stickySelection: ModelSelection | null,
+    ) =>
+      resolveNewTaskModelSelection({
+        draftSelection,
+        projectDefaultSelection,
+        stickySelection,
+        modelOptions: [providerDefault],
+      });
+
+    expect(resolve(draft, project, sticky)).toBe(draft);
+    expect(resolve(null, project, sticky)).toBe(project);
+    expect(resolve(null, null, sticky)).toBe(sticky);
+    expect(resolve(null, null, null)).toBe(providerDefault.selection);
+  });
 });

apps/mobile/src/lib/modelOptions.ts

@@ -104,6 +104,22 @@ export function resolveDefaultableModelSelection(
   return model?.isLegacy === true ? null : usable;
 }
 
+export function resolveNewTaskModelSelection(input: {
+  readonly draftSelection: ModelSelection | null;
+  readonly projectDefaultSelection: ModelSelection | null;
+  readonly stickySelection: ModelSelection | null;
+  readonly modelOptions: ReadonlyArray<ModelOption>;
+}): ModelSelection | null {
+  return (
+    input.draftSelection ??
+    input.projectDefaultSelection ??
+    input.stickySelection ??
+    input.modelOptions.find((option) => option.isDefault)?.selection ??
+    input.modelOptions[0]?.selection ??
+    null
+  );
+}
+
 export function buildModelOptions(
   config: T3ServerConfig | null | undefined,
   fallbackModelSelection: ModelSelection | null,